The electrical properties of Radio Frequency Sputtered NiFeO and NiO films deposited on n and p-type Silicon is investigated for two different oxygen flows. Rectifying properties for Ni0.8Fe0.2O1+ α on n-Si showed Iforward/Ireverse >10,000 for α>0 and Iforward/Ireverse >50 for α<0. Both types of devices have opposite forward biases. Results suggest that NiFeO sputtered at high oxygen flow is p-type. For NiO and NiFeO on p-Si no strong rectifying properties were observed. The specific contact resistivity of Pt/Ni0.9Fe0.1O1+ α (α>0) was estimated from the difference between the two and four-point probe resistances (0.0007 ± 0.0003 Ω cm2). Using density functional theory calculations, density of state and charge density plots were obtained for systems modelled after experiment, showing that states introduced by O vacancies in NiFeO are localized and prefer locations near Ni explaining the observed hysteresis effects in the IV curves of devices sputtered at low oxygen flow.

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When using a Photo-elastic modulator (PEM) in combination with a coherent light source, in addition to the modulation of the phase, Fabry-Perot interference in the PEM’s optical head induces large offsets in the 1ω and 2ω detector signals. A Jones matrix which describes both effects simultaneously, was derived for a single axis PEM and used to find an expression for the detector signal for two different MO Kerr setups. The effect of the PEM tilt angle, polarizer angle, analyzer angle, and retardation, on the detector signal offsets show that offsets can be zeroed by adjusting PEM tilt angle, polarizer angle, and retardation. This strategy will allow one to avoid large offset drifts due to the small retardation, intensity, and beam direction fluctuations caused by lab temperature fluctuations. In addition, it will enable one to measure in the most sensitive range of the lock-in amplifiers further improving the signal to noise ratio of the setup.

The effect of the PEM tilt angle and incident polarization on the PEM interference is studied for a single axis photo-elastic modulator. The dc, 1ω, and 2ω components of the detector signal vary periodically as a function of PEM tilt angle. Although it is possible to adjust the PEM tilt angle to minimize the 1ω or 2ω detector signal at small tilt angles, it is not possible to null both of them simultaneously. For the case where no analyzer is used, the ac detector signals can be minimized simultaneously by adjusting the polarization angle of the light incident on the PEM and the PEM tilt angle. Direct observations of the detector signal indicate that the effects of refraction index and thickness variations are opposite consistent with a lower polarizability for compressive strain of the modulator.